The present invention relates to recording medium formed in the shape of a tape and encased in a cassette to a form a tape cassette, a tape drive to write or read data to or from the tape-shaped recording medium, and a method of discriminating the type of a recording medium loaded in the tape drive.
As a tape drive (tape recording and/or reproducing apparatus) capable of writing and/or reading digital data to and/or from a magnetic tape as a recording medium, a so-called tape streaming device has been proposed. The tape streaming drive can record tens to hundreds gigabytes of data for example. This recording capacity depends upon the length of a magnetic tape in a tape cassette used in the drive. Thus, the tape streaming drive is widely used to back up data recorded in a medium such as a hard disk used in a computer, etc. Also the tape streaming drive is conveniently used to store data having a large size such as image data.
As a typical example of the above-mentioned tape streaming drive, there has been proposed a one adapted to record or reproduce data into or from an 8-mm VTR tape cassette as a recording medium by a helical scanning method in which a rotary head is used.
In the above tape streaming drive, it is first necessary to judge whether or not a tape cassette loaded in the drive is a one supported by the tape streaming drive designed and manufactured under a standard.
Even a tape cassette of a type conforming to the standard for the tape streaming drive has to be judged to be a data storage one or a cleaning cassette.
Further, if there is available a plurality of data formats for the data streaming drive, it is necessary for even a tape cassette meeting the standard for the tape streaming drive to meet one of the data formats the tape cassette supports.
That is, the tape streaming drive has to be adapted to identify the type of a tape cassette loaded therein.
Generally, for identification of a tape cassette type, an identification hole is provided in the body of the tape cassette body and a detection mechanism or the like is provided in the tape streaming drive to detect the identification hole in the tape cassette body. In this case, at the tape streaming drive, the detection mechanism detects whether or not the identification hole is provided in the body of the tape cassette loaded in the drive to identify the type of the tape cassette loaded in the drive. Thus, it is possible to allow the tape streaming drive to operate correspondingly to the tape cassette type thus identified.
The tape streaming drive system has available kinds of data format increased frequently as necessary to improve the recording and reproduction reliability, recording density, etc. for example. Generally, it means that higher-order data formats will be added to the existing data formats. Therefore, along with the increased number of data formats, the tape streaming drive has to support a correspondingly increased number of tape cassette types.
As a matter of fact, however, it is difficult because of the space, etc. to form additional holes in the tape cassette body correspondingly to the addition of data formats. Also, with the addition of the data formats, the structure of the detection mechanism in the tape streaming drive will be complicated and larger in order to detect many identification holes formed in the tape cassette body. In this respect, it is not desirable to form additional identification holes in the tape cassette body correspondingly to the addition of the tape cassette types for use with the tape streaming drive.
Accordingly the present invention has an object to overcome the above-mention drawbacks of the prior art by making it possible to identify the type of tape cassette, especially, a data format of the tape cassette, without dependence upon the identification hole formed in a tape cassette body.
The above object can be attained by providing a recording medium including, according to the present invention:
a magnetic tape;
a cassette encasing the magnetic tape; and
a memory provided in the cassette to store management information for management of data writeN to and/or read from the magnetic tape;
the magnetic tape having a data format for data written to and/or read from the magnetic tape and which corresponds to any of a plurality of predetermined data formats; and
the memory having set therein a storage area for storage of data format identification information indicative of the corresponding data format.
According to another aspect of the present invention, the memory may be provided with terminals for transfer of information signals and which face the outside of the cassette.
According to another aspect of the present invention, the memory may be provided with a transmission and reception means for non-contact transfer of information signal.
According to another aspect of the present invention, the magnetic tape may have an area where an information signal is recorded, and the area be divided in three or more partitions.
According to another aspect of the present invention, system log allocation flags included in data format identification information recorded in the magnetic tape may be adapted to indicate that the data format identification information is recorded in the magnetic tape, and the data formation identification information be read from the magnetic tape when data formation identification information cannot be read from the memory.
According to another aspect of the present invention, it may be judged, based on a native flag included in the data format identification information read from the magnetic tape, which the area of the magnetic tape where the information signal is recorded has, a format in which the area is divided in three or more partitions or a format in which the area is divided in two or less partitions.
Also the above object can be attained by providing a tape drive to write and/or read information signals to and/or from a recording medium comprising a magnetic tape; a cassette encasing the magnetic tape; and a memory provided in the cassette to store management information for management of data written to or read from the magnetic tape; the magnetic tape having a data format for data written to or read from the magnetic tape and which corresponds to any of a plurality of predetermined data formats; and the memory having set therein a storage area for storage of data format identification information indicative of the corresponding data format. In addition, the tape drive according to the present invention includes;
tape driving means for writing and/or reading information signals to and/or from the magnetic tape in the loaded recording medium;
memory reading means capable of reading at least the data format identification information from the management information stored in the memory in the loaded recording medium; and
a data format identifying means for identifying, based on the data format identification information read by the memory reading means, a data format the loaded recording medium has.
According to another aspect of the present invention, the tape drive may further include means may, for controlling the data driving means, the tape driving means write and/or read on information signal in a data format selected from at least two of the plurality of predetermined data formats, and the controlling means allow the tape driving means to write and/or read in the data format identified by the data format identifying means.
According to another aspect of the present invention, the tape drive may further include a hole detecting mechanism to detect a cleaning cassette identification hole formed in the cassette, where it may be judged whether or not the loaded recording medium is a cleaning cassette based on the result of detection of the cleaning cassette identification hole by the hole detecting mechanism. When the recording medium is judged to be a cleaning cassette, a mode of operation in which the cleaning cassette is used is done, while when the recording medium is judged not to be any cleaning cassette, the memory reading means reads the data format identification information from the memory and it may be judged whether the memory is, one provided with terminals for transfer of information signal or one provided with a transmitting and reception means for non-contact transfer of an information signal.
According lo another aspect of the present invention, the tape drive may be adapted such that when the data format identification information cannot be read from the memory, the data format identification information is read from the magnetic tape; when system log allocation flags included in the data format identification information read from the magnetic tape show that the data format identification information is recorded in the magnetic tape, it is judged based on a native flag included in the data format identification information read from the magnetic tape which format the area of the recording medium where the information signal is recorded has, a one in which the area is divided in three or more partitions or a one in which the area is divided in two or less partitions. When it is judged that the area of the magnetic tape in which the information signal is recorded has a format in which the area is divided in three or more partitions, the memory is regarded as being faulty and the magnetic tape is used as a read-only one with prevention of the information signal from being written to the magnetic tape, while when it is judged that the magnetic tape area in which the information signal is recorded has a format in which the area is divided in two or less partitions, the recording medium is regarded as not provided with the memory.
According to another aspect of the present invention, the tape drive may further include:
a hole detecting mechanism for detecting whether or not a write protect hole indicating the prevention of writing of the information signal is formed in the cassette; and
a stripe sensor for optically detecting an identification stripe formed on the magnetic tape; so that:
when the data format identification information cannot be read from the memory and also reading of the data format identification information from the magnetic tape is impossible, it is judged, based on the result of write protect hole detection, Woks whether writing of the information signal is prevented or not;
when it is judged that writing of the information signal is not prevented, the magnetic tape is judged to have the format in which the area of the magnetic tape where the information signal is recorded is divided in two or less partitions;
when it is judged that write of the information signal is prevented, the identification stripe is detected by the stripe sensor; when the identification stripe is not detected, it is judged that the memory is not provided and the area of the magnetic tape where the information signal is recorded has the format in which the area is divided in two or less partitions; and when the identification stripe is detected, reading of the data identification information from the magnetic tape is tried.
According to another aspect of the present invention, the tape drive may be adapted such that when it is judged that the memory is not provided and the area of the magnetic tape where the information signal is recorded has the format in which the area is divided in two or less partitions, the magnetic tape being coped with as a blank tape in which information signal is not yet recorded.
Also the above object can be attained by providing a recording medium type identifying method for identification of a data format of a recording medium to and/or from which an information signal is going to be written and/or from and which comprises a magnetic tape; a cassette encasing the magnetic tape; and a memory provided in the cassette to store management information for management of data written to or read from the magnetic tape; the magnetic tape having a data format for data written to or read from the magnetic tape and which corresponds to any of a plurality of predetermined data formats; and the memory having set therein a storage area for storage of data format identification information indicative of the corresponding data format; the method including, according to the present invention, steps of:
reading at least the data format identification information from the management information stored in the memory in the recording medium used; and
identifying, based on the data format identification information read by the memory reading means, a data format the loaded recording medium has.
According to another aspect of the present invention, the method may further include a step of detecting whether or not a cleaning cassette identification hole is formed in the cassette of the recording medium; when it is judged based on the result of detection of the cleaning cassette identification hole whether the recording medium used is a cleaning cassette or not; when it is judged that the recording medium used is not any cleaning cassette, the data format identification information is read from the memory and it being judged whether which the memory is, a one provided with terminals for transfer of an information signal or a one provided with a transmitting and reception means for non-contact transfer of the information signal.
According to another aspect of the present invention, the method may be adapted such that when the data format identification information cannot be read from the memory, the data format identification information is read from the magnetic tape; when system log allocation flags included in the data format identification information read from the magnetic tape show that the data format identification information is recorded in the magnetic tape, it is judged based on a native flag included in the data format identification information read from the magnetic tape which format the area of the recording medium where information is recorded has, a one in which the area is divided in three or more partitions or a one in which the area is divided in two or less partitions;
when it is judged that the area of the magnetic tape in which the information signal is recorded has a format in which the area is divided in three or more partitions, the memory is regarded as is faulty and the magnetic tape being used as a read-only one with prevention of the information signal from being written to the magnetic tape; and
when it is judged that the magnetic tape area in which the information signal is recorded has a format in which the area is divided in two or less partitions, the recording medium is regarded as not provided with the memory.
According to another aspect of the present invention, the method may be adapted such that when the data format identification information cannot be read from the memory and also reading of the data format identification information from the magnetic tape is impossible, it is judged, based on the result of write protect hole detection, whether writing of the information signal is prevented or not;
when it is judged that writing of the information signal is not prevented, the magnetic tape is judged to have the format in which the area of the magnetic tape where the information signal is recorded is divided in two or less partitions; and
when it is judged that write of the information signal is prevented, the identification stripe is detected by the stripe sensor; when the identification stripe is not detected, it is judged that the memory is not provided and the area of the magnetic tape where the information signal is recorded has the format in which the area is divided in two or less partitions; and when the identification stripe is detected, reading of the data identification information from the magnetic tape is tried.
According to another aspect of the present invention, the method may be adapted such that when it is judged that the memory is not provided and the area of the magnetic tape where the information signal is recorded has the format in which the area is divided in two or less partitions, the magnetic tape is judged to be a blank tape in which the information signal is not yet recorded.